The third O antiphon, O Radix Jesse, takes place on December 19. Here is the Latin:
O Radix Jesse,qui stas in signum populorum, super quem continebunt reges os suum, quem gentes deprecabuntur: veni ad liberandum nos, jam noli tardare.
A somewhat literal translation into English might say;
O Root of Jesse, you stand as a sign among the peoples; before you kings will hold their tongues, and you the Gentiles will seek: come to deliver us, and do not delay.
The scriptural references for this antiphon are from Isaiah 11: 10-11 (“On that day, the Gentiles shall seek out the root of Jesse, set up as a signal for the nations; his dwelling shall be glorious. On that day, the Lord shall again take it in hand to reclaim the remnant of his people.”), as well as Is. 52:15 (“So shall he startle many nations; because of him kings shall stand speechless”), and perhaps from Paul’s quotation of Isaiah in Romans 12:15 (“And again Isaiah says: “The root of Jesse shall come, raised up to rule the Gentiles; in him shall the Gentiles hope”).
As we know, the English words for the ever popular Advent song, “O Come, O Come Emmanuel”, are based on the O Antiphons, but with the last antiphon made first. Here is today’s verse, the one based on O Radix:
“O come, O Rod of Jesse’s stem, from ev’ry foe deliver them
That trust your mighty pow’r to save,
And give them victr’y o’er the grave.
Rejoice! Rejoice! Emmanuel
Shall come to you, O Israel!”
Further reflection here.